Screen



4 (No Model.)

A A. PALM. SCREEN.

No. 444,252. Patented Jan. 6, 1891.

4 UNITED STATES PATENT OFFICE.

ALEXANDER A. PALM, OF CALICO, CALIFORNIA.

SCREEN.

SPECIFICATION forming part of Letters Patent No. 444,252, dated January 6, 1891. Application filed August 12, 1890- Serial No. 361,826. (No model.)

T 0 a whom it may concern Be it known that I, ALEXANDER A. PALM, a citizen of the United States, residing at Calico, San Bernardino county, State of California, have invented an Improvement in Screens; and I hereby declare the followingto be a full, clear, and exact description, ofthe same.

My invention. relates to the general class of screens, and especially to that sub-class adapted to screen heavy substances, such as ore and coal, and commonly known as grizzlies.

My invention consists in the novel construction and arrangement hereinafter fully described, and particularly pointed out in the claims.

The object of my invention is to provide a simple and effective screen of this class adapted for all kinds of screening, but particularly for heavier substances, such as ore and coal.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure 1 is a side elevation of one of my grizzly-bars. Fig. 2 is a plan of same. Fig. 3 is a cross-section. Fig. at is a side elevation of my completed grizzly. Fig. 5 is a plan of same.

The screen or grizzlybarsA are solid strong metal bars, preferably of cast-iron. In crosssection, Fig. 3, they taperdownwardly, in plan, Fig. 2, they taper toward one end, and in elevation, Fig. 1, they taper toward the other end. Regardingthe bar when in position, its lower end a is bent substantially at right angles and has one or more holes a. through it, while its upper end has a hole a In Figs. 4 and 5,13 are suitable supports for the bars A.

The grizzly is arranged at an inclination, as shown in Fig. 4. Any angle will answer which is sufficient to make an incline to insure the free downward course of the material. An angle of forty-five degrees is a good one. The bars A are arranged in sections side by side, Fig. 5, their upper ends resting on the supports above and their lower bent ends resting upon the supports below, and, as seen in Fig. 4, on account of these bent ends a drop-oft is made between one section of bars and the next section below.

The relative arrangement of the bars in one section to those in the next is a point to be noted. Referring to Fig. 5, it will be seen that the narrow and bent lower ends of the bars of an upper section lie between the wide upper ends of the bars of the succeeding lower section, and bolts 0 pass through the holes a in the upper ends of the lower bars and the holes a in the bent lower ends of the upper bars, whereby all the bars are secured together. This results in lining up the openings or spaces between the bars of one section with the bars themselves of adjacent sectionsthat is to say, a bar in one section is succeeded by a space in the next section. The advantage of this is that a piece of material coming down the bar of .an upper section will find the opening in the next section directly in its path, so that there is no danger of a piece which can be screened passing down upon the bars throughout the whole length of the grizzly. Between the upper ends of the bars of the uppermost section and between the lower ends of the bars of the lowermost section washers D are placed and secured by the crossbolts,therebyholdingthebarsproperlyspaced. On account of the tapering shape of the bars in plan it will be seen that the spaces or openings between them are wider at their lower than at their upper ends, which avoids clogging or wedging andinsures proper discharge. This result is further insured by the tapering shape in cross-section of the bars.

The advantage of the drop-0E formed by the bent lower ends of the bars is that the speed of the material will be checked, giving it a better opportunity to be screened, and this drop-off in connection with the lining up of bars and openings or spaces, heretofore mentioned, is of advantage in better directing the material to said openings or spaces.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a screen or grizzly, the several sections thereof composed of independent separated bars, the lower ends of the bars of one section lying between the upper ends of the bars of the succeeding section, whereby the spaces between the bars in one section are in line with the bars in the succeeding section, and a rod or bar passing through the lower and upper ends, respectively, of adjoining bars, substantially as herein described.

2. In a screen or grizzly, the several sections thereof composed of separated bars, the

5 lower end of each bar being bent and passing down into and lying between the upper ends of adjacent bars of the succeeding section, and bolts passin through the ends of the bars, whereby they are held together, substantially 10 as herein described.

15 bars having holes formed in their upper and lower ends, washers between the upper ends of the bars of the uppermost section and between the lower ends of the bars of the lowermost section, and bolts passing through the adjacent ends of all the bars and through the washers, substantially as herein described.

4:. In a screen or grizzly, the several sections thereof composed of independent separated bars tapering downwardly in plan and cross-section, as described, and each bar havinga bent lowerend lying between the upper ends of the bars of succeeding sections, and each bar havingholes in opposite ends through which uniting bolts pass, substantially as herein described.

In Witness whereof I have hereunto set my hand.

ALEXANDER A. PALM. WVitnesses:

THOMAS PRESTON, ISAAC NORTON, Jr. 

